Document the fact that __save_processor_state() has to save all CPU
registers referred to by the kernel in case a different kernel is
used to load and restore a hibernation image containing it.
Sigend-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Michael Opdenacker reported:

For backward compatibility with earlier (< 2.6.24) kernels,
arch/i386/boot/bzImage or arch/x86_64/boot/bzImage symbolic links to
arch/x86/boot/bzImage are created when you build an x86 kernel. The
arch/i386 or arch/x86_64 directories are then created for this only
purpose.

Issue: these generated directories and symbolic links are *not cleaned
up* when you run "make mrproper" (and thus "make distclean"). This
disturbs the production of patches, because the source tree is left with
generated files and directories.

Sam has an alternative fix:

The directory is killed during make clean as opposed to make mrproper.
Reported-by: NMichael Opdenacker <michael-lists@free-electrons.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Current idle time in kstat is based on jiffies and is coarse grained.
tick_sched.idle_sleeptime is making some attempt to keep track of idle time
in a fine grained manner.  But, it is not handling the time spent in
interrupts fully.

Make tick_sched.idle_sleeptime accurate with respect to time spent on
handling interrupts and also add tick_sched.idle_lastupdate, which keeps
track of last time when idle_sleeptime was updated.

This statistics will be crucial for cpufreq-ondemand governor, which can
shed some conservative gaurd band that is uses today while setting the
frequency.  The ondemand changes that uses the exact idle time is coming
soon.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

I recently noticed on one of my boxes that when synched with an NTP
server, the drift value reported for the system was ~283ppm. While in
some cases, clock hardware can be that bad, it struck me as unusual as
the system was using the acpi_pm clocksource, which is one of the more
trustworthy and accurate clocksources on x86 hardware.

I brought up another system and let it sync to the same NTP server, and
I noticed a similar 280some ppm drift.

In looking at the code, I found that the acpi_pm's constant frequency
was being computed correctly at boot-up, however once the system was up,
even without the ntp daemon running, the clocksource's frequency was
being modified by the clocksource_adjust() function.

Digging deeper, I realized that in the code that keeps track of how much
the clocksource is skewing from the ntp desired time, we were using
different lengths to establish how long an time interval was.

The clocksource was being setup with the following interval:
	NTP_INTERVAL_LENGTH = NSEC_PER_SEC/NTP_INTERVAL_FREQ

While the ntp code was using the tick_length_base value:
	tick_length_base ~= (tick_usec * NSEC_PER_USEC * USER_HZ)
					/NTP_INTERVAL_FREQ

The subtle difference is:
	(tick_usec * NSEC_PER_USEC * USER_HZ) != NSEC_PER_SEC

This difference in calculation was causing the clocksource correction
code to apply a correction factor to the clocksource so the two
intervals were the same, however this results in the actual frequency of
the clocksource to be made incorrect. I believe this difference would
affect all clocksources, although to differing degrees depending on the
clocksource resolution.

The issue was introduced when my HZ free ntp patch landed in 2.6.21-rc1,
so my apologies for the mistake, and for not noticing it until now.

The following patch, corrects the clocksource's initialization code so
it uses the same interval length as the code in ntp.c. After applying
this patch, the drift value for the same system went from ~283ppm to
only 2.635ppm.

I believe this patch to be good, however it does affect all arches and
I've only tested on x86, so some caution is advised. I do think it would
be a likely candidate for a stable 2.6.24.x release.

Any thoughts or feedback would be appreciated.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Looks like IRQ 31 is assigned to timer 3, even without the patch!
I wonder who wrote the number 31. But the manual says that it is
zero by default.

I think we should check whether the timer has been allocated an IRQ before
proceeding to assign one to it.  Here is a patch that does this.
Signed-off-by: NBalaji Rao <balajirrao@gmail.com>
Tested-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The userspace API for the HPET (see Documentation/hpet.txt) did not work. The
HPET_IE_ON ioctl was failing as there was no IRQ assigned to the timer
device. This patch fixes it by allocating IRQs to timer blocks in the HPET.

arch/x86/kernel/hpet.c |   13 +++++--------
drivers/char/hpet.c    |   45 ++++++++++++++++++++++++++++++++++++++-------
include/linux/hpet.h   |    2 +-
3 files changed, 44 insertions(+), 16 deletions(-)
Signed-off-by: NBalaji Rao <balajirrao@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

detect zero event-device multiplicators - they then cause
division-by-zero crashes if a clockevent has been initialized
incorrectly.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The following scenario might leave PIT as a disfunctional clock source:

    PIT is registered as clocksource
    PM_TIMER is registered as clocksource and enables highres/dyntick mode
    PIT is switched to oneshot mode
    -> now the readout of PIT is bogus, but the user might select PIT
    via the sysfs override, which would break the box as the time
    readout is unusable.

Unregister the PIT clocksource when the PIT clock event device is switched
into shutdown / oneshot mode.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

On x86 the PIT might become an unusable clocksource. Add an unregister
function to provide a possibilty to remove the PIT from the list of
available clock sources.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

PIT clocksource is registered unconditionally even when HPET is enabled
or when PIT is replaced by the local APIC timer. In both cases PIT can
not be used as it is stopped and the readout would be stale.

Prevent registering PIT in those cases.

patch depends on:

  x86: offer is_hpet_enabled() on !CONFIG_HPET_TIMER too
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

offer is_hpet_enabled() on !CONFIG_HPET_TIMER too.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This way it checks if the clocks are synchronized between CPUs too.
This might be able to detect slowly drifting TSCs which only
go wrong over longer time.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

clocksource_watchdog can use a deferrable timer - reduces wakeups from
idle per second.
Signed-off-by: NParag Warudkar <parag.warudkar@gmail.com>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  - getnstimeofday() was just a wrapper around __get_realtime_clock_ts()
  - Replace calls to __get_realtime_clock_ts() by calls to getnstimeofday()
  - Fix bogus reference to get_realtime_clock_ts(), which never existed
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

clean up tick-broadcast.c
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
fixes. When there's copyright, there should be GPL.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Small cleanups to tick-related code. Wrong preempt count is followed
by BUG(), so it is hardly KERN_WARNING.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Clean up hungarian notation from timer code.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

the logic in this function is just crazy.  It's recursive, but we
can circumvent the creation for the kobject and whole creation of the
threshold_block if some conditions are met.  That's why we see the
allocate_threshold_blocks so many times in the callstack, yet only a few
kobjects created.

Then we blow up in kobject_uevent_env() on the first debug printk.
Which means that we are just passing in garbage.

Man, this is one time that comments in code would have been very nice to
have, and why forward goto's into major code blocks are just evil...
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

* git://git.linux-nfs.org/pub/linux/nfs-2.6: (118 commits)
  NFSv4: Iterate through all nfs_clients when the server recalls a delegation
  NFSv4: Deal more correctly with duplicate delegations
  NFS: Fix a potential race between umount and nfs_access_cache_shrinker()
  NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
  nfs: convert NFS_*(inode) helpers to static inline
  nfs: obliterate NFS_FLAGS macro
  NFS: Address memory leaks in the NFS client mount option parser
  nfs4: allow nfsv4 acls on non-regular-files
  NFS: Optimise away the sigmask code in aio/dio reads and writes
  SUNRPC: Don't bother changing the sigmask for asynchronous RPC calls
  SUNRPC: rpcb_getport_sync() passes incorrect address size to rpc_create()
  SUNRPC: Clean up block comment preceding rpcb_getport_sync()
  SUNRPC: Use appropriate argument types in rpcb client
  SUNRPC: rpcb_getport_sync() should use built-in hostname generator
  SUNRPC: Clean up functions that free address_strings array
  NFS: NFS version number is unsigned
  NLM: Fix a bogus 'return' in nlmclnt_rpc_release
  NLM: Introduce an arguments structure for nlmclnt_init()
  NLM/NFS: Use cached nlm_host when calling nlmclnt_proc()
  NFS: Invoke nlmclnt_init during NFS mount processing
  ...

If the two requests belong to the same io context, we will attempt
to lock the same lock twice. But swapping contexts is pointless in
that case, so just check for rioc == nioc before doing the double
lock and copy.
Tested-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The same delegation may have been handed out to more than one nfs_client.
Ensure that if a recall occurs, we return all instances.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If a (broken?) server hands out two different delegations for the same
file, then we should return one of them.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Thanks to Yawei Niu for spotting the race.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

use NFS_I(inode)->flags instead
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

David Howells noticed that repeating the same mount option twice during an
NFS mount request can result in orphaned memory in certain cases.

Only the client_address and mount_server.hostname strings are initialized
in the mount parsing loop, so those appear to be the only two pointers that
might be written over by repeating a mount option.  The strings in the
nfs_server section of the nfs_parsed_mount_data structure are set only once
after the options are parsed, thus these are not susceptible to being
overwritten.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The rfc doesn't give any reason it shouldn't be possible to set an
attribute on a non-regular file.  And if the server supports it, then it
shouldn't be up to us to prevent it.

Thanks to Erez for the report and Trond for further analysis.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Tested-by: NErez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There are no interruptible waits for asynchronous RPC tasks, so we don't
need to wrap calls to rpc_run_task() with an
rpc_clnt_sigmask/rpc_clnt_unsigmask pair.

Instead we can wrap the wait_for_completion_interruptible() in
nfs_direct_wait(). This means that we completely optimise away sigmask
setting for the case of non-blocking aio/dio.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The caller will never sleep in rpc_execute, so don't bother setting the
sigmask.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The variable "sin" is a pointer, so sizeof(sin) is the size of a pointer,
not the size of thing that sin points to.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: Follow recommendations of Chapter 5 of Documentation/CodingStyle
and use "u32" instead of "__u32" for types in definitions that are not
shared with user space.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

rpc_create() can already fill in the hostname with a string representation
of the server's IP address, so remove redundant logic in in
rpcb_getport_sync() that does that.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: document the rule (kfree) and the exceptions
(RPC_DISPLAY_PROTO and RPC_DISPLAY_NETID) when freeing the objects in
a transport's address_strings array.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

RPC protocol version numbers are unsigned.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: pass 5 arguments to nlmclnt_init() in a structure similar to the
new nfs_client_initdata structure.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>